Should analytical chemists (and their customers) trust the normal distribution?

Abstract

The normal distribution, under its popular name ‘the bell curve’, has attracted adverse criticism in recent years, owing mainly to being prominently featured in some well-publicised books on socio-economic topics. A number of conclusions in these fields, ranging from questionable to spectacularly incorrect, have been drawn from an ill-considered use of the bell curve as a statistical tool. Those application sectors do not directly impinge on chemical measurement but the toxic fallout has been widespread and likely to bias the reading public against inferences based on the normal distribution. It is therefore essential that analytical chemists should be able to recognise appropriate and inappropriate uses of the normal distribution and to defend their decisions adequately when working alongside those unfamiliar with measurement and statistics.